qwntia

Wikipedia says, "An underweight person is a person whose body weight is considered too low to be healthy." Impaired mental development sounds unhealthy to me, so this suggests CR wouldn't inhibit mental development as long as you avoid being underweight. Does this sound reasonable to you all?

According to this, eating disorders can indeed cause brain damage. Of course, this doesn't mean CR does due to CR practitioners having good nutrition and perhaps less extreme restriction of calories. (I take it when you say prefrontal lobe you mean prefrontal cortex.) Interesting. What is your evidence for this?

Thanks for the input. That said, since your experience is a case study and since it's hard to determine what your intelligence would have been if you kept a higher BMI (because there's no control group), the evidence your experience provides is extremely weak. It does provide significant evidence that starting CR when ~18 doesn't have a massive effect on intelligence, but I wouldn't have thought there was one, a priori, considering brain already undergo a lot of development before the age of 18 (18-year-olds aren't that dumb, after all).

By CR I mean calorie restriction, of course. What else did you want specified? For instance, I consider myself "doing CR" because I eat fewer calories than I did when I was true "ad lib" feeding, and fewer calories than an average American of my height and gender. Others here seem to have different criteria. At any rate, serious calorie restriction will impact both physical and mental growth and development. Some would argue that this is the goal, so what's the problem? On the other hand if your idea of CR just means eating lots of fruits and veges and not allowing yourself to be overweight, then you are golden. Thank you for the explanation. Do you know of any resources to help estimate the minimum amount of calories needed to avoid inhibiting brain development for someone whose brain is not yet fully developed? I know one is considered underweight if one's BMI is less than 18.5, so I was wondering if restricting caloric intake would be okay if BMI is kept above that.

By CR I mean calorie restriction, of course. What else did you want specified?

This says: children, adolescents, and young adults (under approx 21) should be advised against starting CR. Physical growth may be impaired by calorie restriction, as observed in lab animals. In addition, mental development and physical changes to the brain take place in late adolescence and early adulthood that could be negatively affected by calorie restriction. For this group, the best advice is to follow a normal (non-CR) diet until reaching early twenties. However, according to this, brain development continues "well into our 20s" (i.e. beyond approx 21). I am wondering if starting CR in one's early or mid 20s would impair brain development. I recall reading that CR can also slow brain deterioration, though, so it might be the case that starting CR in one's early or mid 20s would still be a net positive for brain functioning in the long term. Any relevant insights would be appreciated.